About three months before the start of next school year, the Indianapolis Public Schools district is rolling out new schedules for some of its schools.

The district is moving to a two-tier model for its bell schedule, when school starts and ends for the day. It was approved unanimously by the school board Thursday night.

Most middle and high schools will operate on the early schedule, starting at 7:20 a.m. and ending at 2:10 p.m. Shortridge High School will keep its current schedule, operating from 9:15 a.m. to 4 p.m.

Most elementary schools will operate on the later schedule, from 9:20 a.m. to 3:55 p.m.

The majority of IPS schools will either keep their current schedule or have it adjusted by no more than 10 minutes. All 12 schools that are currently on the district's "middle tier," running from 8:15 to 2:50 p.m., will move to the later tier — a 65-minute shift. Lew Wallace School 107 currently operates from 7:45 a.m. to 2:20 p.m. and will shift 25 minutes earlier, to match up with the new first tier.

District officials have said a move to a two-tier transportation system, rather than the current three tiers, is necessary to provide more efficient, cost-effective bus service, but some parents are raising concerns about making the switch.

"I'm very concerned that we're having this conversation in April, after the second round of school choice has closed and when parents have been making the decision about where to send their kids to school since November," said Dustin Jones, a parent with two children in IPS schools.

IPS is using a new enrollment system this year, called OneMatch. Families are able to select and rank their most desired schools and the system matches them based on space and a variety of priority factors. There are three enrollment windows; the second closed April 15.

Some of the need for a new schedule comes from the planned move to an all-choice model for high schools next year. Currently, the district uses a neighborhood model for most of its high schools, limiting cross-town bus trips. Next year, all high school students will go to one of four centrally located campuses and the added transportation needs could stress the already-taxed system.

District officials started the conversation about new bell times several months ago, but some parents balked at initial proposals that were radical, including a much later schedule for high schools.

While research supports later school start times for older students, family surveys did not find a consensus for such a change. District officials said many high school students work or watch younger students, so a later schedule could hurt those families.

Last month, board members requested staff go back to the drawing board and collect more information from families.

For the final proposal, the district worked to keep dismissal times earlier and all schedules as close as possible to the times they operate on this year.

This will be the third bell time schedule in as many years for IPS schools. The current three-tier system was new this year. Board member Kelly Bentley asked for assurances that the district would maintain the new schedule for some time.

"It causes a huge disruption to families," Bentley said.

Superintendent Lewis Ferebee said he would like to make that commitment, but it will depend on the outcome of the district's planned referendum. IPS intends to put a property tax hike on the November ballot to pay for things like salaries and transportation.

IPS expects to spend a little more than $45 million on transportation this year. It has budgeted $47.6 million for next year, nearly $13 million over the transportation funding it expects to receive from the state.

The district is looking for ways to save money on transportation. It will launch a public transit pilot with IndyGo at Shortridge High School in May. If the pilot goes well, the district hopes to eventually move to public transit for all high schools.